SK279680B6 - Tool for a tool holder of hand-held tools - Google Patents

Abstract

A chucking shank (9) is provided with two diametrically opposite rotary driving grooves (10) opening axially toward the free end of the chucking shank (9). Further, two diametrically opposite locking grooves (11) are provided, whose length is exceeded on both sides by two diametrically opposite longitudinal grooves (12). The axial projection of the longitudinal grooves (12) lies within the axial projection of the locking grooves (11) so that the areas of the locking grooves (11) which are not overlapped form shoulder surfaces (11b). The flanks of the longitudinal grooves (12) are selected in such a way that the flanks (12a) on the driving side substantially form a tangent to the base of the locking grooves (11) and the flanks (12b) located opposite. The opening edges (12c) of the longitudinal grooves (12) coincide with the opening edges (11a) of the locking grooves (11). The cross-section of both the rotary driving grooves (10) and both the longitudinal grooves (12) has the form of a trapezoid, and, the cross-section of both the locking grooves (11) has a concave form.

Description

Technical field

BACKGROUND OF THE INVENTION The invention relates to a hand-held tool, in particular for hammering and drilling, comprising a clamping shank in which at least one axially closed locking groove is formed and at least two driving grooves axially open to the free end of the clamping shank.

BACKGROUND OF THE INVENTION

DE-PS 25 51 125 discloses known hand-held tools comprising a shank having one or two closed locking grooves and one or two open rotation driving grooves for insertion into an axial clamping device having one or two radial sliding blocking elements, which in this case are ball-shaped. In addition to these balls, it is also known to provide blocking elements in the form of cylinders. Due to the interaction of the locking elements with the axially closed locking grooves, a form-fitting connection is created between the tool and the clamping device. By radially extending the locking elements, this positive connection can be canceled so that the tools can be removed from the clamping device.

Said locking grooves, including co-operating locking elements, are not subject to particularly high demands, since during operation the tool has a practically floating bearing in relation to the locking elements, i.e., in the clamping device. j. The blocking elements do not transmit any large forces in operation in conjunction with the blocking grooves. Only when the tool is removed from the bore in the components, certain axial forces are transmitted through the locking grooves when interacting with the locking elements, thereby ensuring that the connection between the tool and the clamping device is maintained.

However, the rotation drive grooves, which are open towards the free end of the shank, are subjected to extremely high stresses, in which the corresponding drive bars of the clamping device engage. This high stress originates from the torque transmitted from the chuck to the tool. This torque is all the greater the larger the diameter of the tool. Recent trends in the increased use of tools with a larger tool diameter for hand tools result in extremely high wear torques in the swiveling grooves such that wear of the tools is premature. This discarding, caused by the rotating driving grooves, can occur considerably earlier than normal wear caused by the use of the tools as intended.

The arrangement of the larger driving grooves to achieve a larger engagement area corresponding to the transmitted torque fails because it thereby weakens the cross-section of the clamping shank and because there is a pre-programmed failure due to such cross-section weakening. The arrangement of the other rotation driving grooves fails in space because the surface of the clamping shank is already occupied by axially closed locking grooves and further interventions on the surface would severely impair the guidance of the tool. EP 355 071 describes a known tool with a shank whose surface is occupied by three axially closed locking grooves. This known solution has one rotation drive groove having common and corresponding dimensions, and one rotation drive groove, adjoining the blocking groove on both sides, but of substantially smaller dimensions. A disadvantage of this known solution is the considerable loss of transmitted torque and line quality due to the locking grooves that occupy a significant portion of the clamping shank surface.

SUMMARY OF THE INVENTION

The aforementioned drawbacks are largely eliminated by the tool for hammering and drilling with a hammer drill consisting of a clamping shank in which at least one axially closed locking groove and at least two driving grooves axially to the free end of the clamping shank are formed, which consists essentially of in that at least one longitudinal groove axially to the free end of the shank is formed in the clamping shank and which has different distances to the circumferentially adjacent driving grooves in the circumferential direction. The longitudinal groove and the locking groove overlap in their axial diameter, and the extent of the locking groove not overlapped by the longitudinal groove axial projection forms a support surface.

The advantage of this embodiment is that the tool ensures, in particular, in conjunction with a suitable clamping device, the transmission of greater torques without susceptibility to wear, wherein the longitudinal groove does not weaken the clamping shank or significantly reduce the surface serving to guide the clamping shank. Therefore, there is also no loss of quality of the tool guide according to the invention, although the total area of engagement required for torque transmission is substantially increased.

According to a preferred embodiment, two longitudinal grooves are formed in the clamping shank, the axial projections of which overlap the axial projections of the two locking grooves and the extent of the locking grooves not overlapped by the axial projection of the longitudinal grooves forms the abutment surface.

The advantage of this embodiment is that the opposing surfaces thus created are fully sufficient for the proposed tool, since almost no forces are transmitted in the axial direction.

According to a further preferred embodiment, the two longitudinal grooves and the two locking grooves in the clamping shank are each diametrically opposed.

The advantage of this embodiment is that the decisive total area of engagement is increased sufficiently for torque transmission without further weakening the cross-section of the clamping shank and avoiding decisive portions of the surface serving to guide the tool. By placing the longitudinal grooves and the locking grooves diametrically opposite each other, a uniform force distribution is achieved and, in addition, manufacturing advantages are obtained in that, in the event of a non-shear production, for example by extrusion, the press jigs can be arranged opposite each other.

According to a further preferred embodiment, the axes of symmetry of the longitudinal grooves form an acute first angle with the axes of symmetry of the locking grooves.

The advantage of this embodiment is the ideal torque load of the tool and the optimal use of non-overlapping portions of axial projection surfaces as support surfaces for axial seating of the tool.

According to a further preferred embodiment, the longitudinal grooves extend by their length the axial length of the locking grooves.

The advantage of this embodiment is a sufficient increase in the required overall engagement area for torque transmission, this length dimension of the longitudinal grooves causing no further weakening of the cross-section of the clamping shank and additionally contributes to optimum guidance.

According to a further preferred embodiment, the axial projection of the longitudinal grooves is smaller than the axial projection of the locking grooves.

The advantage of this embodiment is that. that the cross-section of the clamping shank is not weakened and the determination of such a dimension has a positive effect on the formation of the abutment surface necessary for axially holding the tool.

According to a further preferred embodiment, the total axial projection of the longitudinal grooves lies within the axial projection of the locking grooves.

The advantage of this embodiment is that it prevents the cross-section of the clamping shank from thinning.

According to a further preferred embodiment, the first orifice edges of the locking grooves and the second orifice edges of the longitudinal grooves coincide.

The advantage of this embodiment is that no harmful deformation forms occur and, moreover, such an embodiment will facilitate the manufacturing process in that the preparations required for this purpose can be simplified so that their service life is increased.

According to a further preferred embodiment, the longitudinal grooves have radially extending surfaces on the driving side.

An advantage of this embodiment is that optimum ratios are achieved in terms of torque transmission.

According to a further preferred embodiment, at least on the driving side of the longitudinal grooves, it runs rectilinearly and the bottom of the locking grooves has the shape of a circular arc. The surface on the drive side of the longitudinal grooves forms a tangent to the bottom of the locking grooves.

The advantage of this embodiment is that there is no edge forming at the passages between the longitudinal grooves and the locking grooves, which promotes wear of the locking elements.

According to a further preferred embodiment, at least the surface on the driving side of the longitudinal grooves has a convex shape and the bottom of the locking grooves has the shape of a circular arc. The surfaces on the drive side and the bottom of the locking grooves intersect.

The advantage of this embodiment is that in any case it avoids the damaging effects of deformation shapes on the tool.

According to a further preferred embodiment, at least the surface on the drive side of the longitudinal grooves has a concave shape and the bottom of the locking grooves has a circular arc shape. The drive side surface and the bottom part of the locking grooves coincide.

The advantage of this embodiment is to prevent the formation of deformation shapes, to reduce wear and to create a flawless optical impression of the clamping shank.

According to a further preferred embodiment, the longitudinal grooves have opposing surfaces on the driving side of the second surface which are rectilinear and which form a second angle with the axis of symmetry of the locking grooves.

The advantage of this embodiment is that there is no inconvenience caused by undercutting with respect to the application of the molding compositions.

According to a further preferred embodiment, the longitudinal grooves have opposing surfaces on the driving side of the second surface having a convex shape.

The advantage of this embodiment is the optimal dimensioning of the longitudinal bars of the clamping device.

According to a further preferred embodiment, the longitudinal grooves have opposing surfaces on the driving side of the second surface having a concave shape.

The advantage of this embodiment is the optimal shaping of the longitudinal strips of the clamping device, especially in terms of strength, whereby both the longitudinal grooves and the co-operating longitudinal strips are shaped as a symmetrical profile.

BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a first embodiment of a tool in a hand tool with a shank; FIG. 2 is a cross-sectional view of the shank of FIG. 2 along line Π-Π, fig. 3 is a side view of a second embodiment of a hand tool with a shank; FIG. 4 is a cross-sectional view of the shank of FIG. 3 along line IV-IV, FIG. 5 is a side view of a third embodiment of a tool in a hand tool with a shank; FIG. 6 is a cross-sectional view of the shank of FIG. 5 along line VI-VI, FIG. 7 shows a longitudinal section of a schematically illustrated clamping device with a shank, FIG. 8 is a cross-sectional view of the clamping device of FIG. 7 along line VIII-VIII, FIG. 9 is a cross-sectional view of a fourth embodiment of a hand tool with a shank; FIG. 10 is a cross-sectional view of a straightforward embodiment of a tool for a hand tool with a shank; and FIG. 11 is a cross-sectional view of a sixth embodiment of a tool for hand tools with a shank.

DETAILED DESCRIPTION OF THE INVENTION

The hand tool of FIG. 1 and 2 consists of a clamping shank 1 in which two diametrically opposed pivoting driving grooves 2 are formed whose longitudinal axes are parallel to the longitudinal axis of the clamping shank 1. The two driving grooves 2 are open axially to the free end of the clamping shank 1. In the shank 1 two mutually diametrically opposed locking grooves 3 are formed whose longitudinal axes are parallel to the longitudinal axis of the shank 1 and whose transverse axis is perpendicular to the transverse axis of the rotation grooves 2. Both locking grooves 3 are axially closed. One longitudinal groove 4 is formed in the shank 1, the longitudinal axis of which is parallel to the longitudinal axis of the shank 1. The longitudinal groove 4 is formed along the entire length of one locking groove 3, which intersects at both its ends. The axial projection of the longitudinal groove 4 lies within the axial projection of the locking groove 3. The extent of the locking groove 3, not overlapped by the axial projection of the longitudinal groove 4, forms the abutment surface 3b.

As shown in particular in FIG. 2, the transverse cross-section of the longitudinal groove 4 is V-shaped, its driving surface 4a extending radially and tensely to the bottom of the locking groove 3. The first edge 3a of the opening of the locking groove 3 is identical to the second edge 4b 4. The cross-section of the two driving grooves 2 has a trapezoidal shape and the cross-section of the two locking grooves 3 has a concave shape.

The hand tool of FIG. 3 and 4 consists of a clamping shank 5 in which two diametrically opposed pivoting driving grooves 6 are formed, the longitudinal axes of which are parallel to the longitudinal axis of the clamping shank 5. The two driving grooves 6 are open axially to the free end of the clamping shank 5. In the clamping shank 5 two mutually diametrically opposed locking grooves 7 are formed, whose longitudinal axes are parallel to the longitudinal axis of the clamping shank 5, and whose transverse axis is perpendicular to the transverse axis of the rotation grooves 6. Both locking grooves 7 are axially closed. In the clamping shank 5 two diametrically opposed longitudinal grooves 8 are formed whose longitudinal axes are parallel to the longitudinal axis of the shank 5. Each longitudinal groove 8 is formed along the entire length of the respective locking groove 7, which it intersects at its two ends. The axial projection of each longitudinal groove 8 lies within and overlaps with the axial projection of the respective locking groove 7. The extent of the locking grooves 7, not covered by the axial projection of the longitudinal grooves 8, forms the abutment surfaces 7a.

As shown in particular in FIG. 4, the cross-section of the longitudinal grooves 8 has a trapezoidal shape. Each longitudinal floor 8 has a driving surface 8a. The cross-section of the two drive grooves 6 has a trapezoidal shape and the two locking grooves 7 have a concave shape. The symmetry axes L of the longitudinal grooves 8 are eccentric and parallel to the symmetry axis V of the locking grooves 7. The hand tool of FIG. 5 and 6 consists of a chuck 9 in which two diametrically opposed pivot driving grooves 10 are formed, the longitudinal axes of which are parallel to the longitudinal axis of the shank

9. The two drive grooves 10 are open axially to the free end of the shank 9. In the shank 9 two mutually diametrically opposed locking grooves 11 are formed whose longitudinal axes are parallel to the longitudinal axis of the shank 9 and whose transverse axis is perpendicular to the transverse axis of the rotation grooves 10. Both locking grooves 11 are axially closed. In the clamping shank 9 two diametrically opposed longitudinal grooves 12 are formed whose longitudinal axes are parallel to the longitudinal axis of the shank 9. Each longitudinal groove 12 is formed along the entire length of the respective locking groove 11, which intersects at both its ends. The axial projection of each longitudinal groove 12 lies within the axial projection of the respective locking groove 11a and overlaps with it. The extent of the locking grooves 11, not covered by the axial projection of the longitudinal grooves 12, forms the abutment surfaces 11b.

As shown in FIG. 6, the cross-section of the longitudinal grooves 12 has a trapezoidal shape. The axes of symmetry L of the longitudinal grooves 12 form an acute first angle with the axis V of the symmetry of the locking grooves 11 in the range of 10 ° to 30 °. However, each longitudinal groove 12 has a drifting side surface 12a that forms a tangent to the bottom of the locking grooves 11a but a second opposite surface 12b that is identical to the axis V of the locking grooves 11. The first edge 11a of the locking grooves 11 is identical to the second edge 12c The cross-section of the two rotation driving grooves 10 is trapezoidal in shape and the two locking grooves 11 are concave in shape.

In FIG. 7 and 8 show clamping devices, for example for clamping the tools according to FIG. 5 and 6, which consists of a cage 15 in which the control sleeve 14 is accommodated, in which the guide 13 is arranged, which has two diametrically opposed driving strips 13a for insertion into the rotation driving grooves 10 and two diametrically opposed longitudinal strips 13b on For example, two mutually diametrically opposed locking elements 16 are displaceable in a radial direction in the inner space 13c of the guide 13 for insertion into the locking grooves 11. The locking elements 16 according to FIG. 5 and 6 are spherical in shape. By rotating or longitudinally sliding the control sleeve 14 against the guide 13, the locking elements 16, which have known and not shown recesses, are pushed out of the locking grooves 11 and, after sliding them out, leave the clearance of the guide 13, releasing the clamping shank 9.

In FIG. 9 shows a clamping shank 17 that is almost identical to the clamping shank 9 shown in FIG. 5 and 6, and which also consists of two pivoting driving grooves 18, two locking grooves 19 with a supporting surface 19a, two longitudinal grooves 20 with a driving side surface 20a and a second driving surface 20b. The drive side surface 20a has a convex shape. The bottom of the locking groove 19 intersects the bottom of the longitudinal groove 20. The second surface 20b of the animal has an axis V of the symmetry of the locking grooves 19 away from the driving side surface 20a by an acute second angle b in the range of 2 ° to 10 °.

In FIG. 10 shows a clamping shank 21 that is almost identical to the clamping shank 17 shown in FIG. 9, and which also consists of two rotation grooves 22, two locking grooves 23 with a support surface 23a, two longitudinal grooves 24 with a drive side surface 24a and a second surface 24b. The second surface 24b has a convex shape.

In FIG. 11 shows a clamping shank 25 that is nearly identical to the clamping shank 9 shown in FIG. 5 and 6, which also consists of two rotation driving grooves, two locking grooves 27 with support surface 27a, two longitudinal grooves 28 with driving surface 28a and a second surface 28b having a concave shape and intersecting in the axis of symmetry L The groove-side surface 28a has the same curvature as the bottom of the locking grooves 27. The first opening edges 27b of the locking grooves 27 are identical to the second opening edges 28c of the longitudinal grooves 28.

The cross-section of the longitudinal grooves 4, 8, 12, 20, 24, 28 may have any shape, in particular a trapezoidal or triangular shape. The longitudinal groove 4, 8, 12, 20, 24, 28 has different distances to the circumferentially adjacent driving grooves 2, 6, 10, 18, 22, 26. The axial projection of the longitudinal grooves 4, 8,12,20,24,28 is less than the axial projection of the locking grooves 3, 7,11,19, 23, 27. The first edges 3a, 11a, 27b of the opening of the locking grooves 3,11, and the second the edges 4b, 12c, 28c of the longitudinal grooves 4, 12, 28 coincide.

The hand tool according to the invention can be produced in a chip or chipless manner, for example by extrusion. In the case of chip machining, it is practically possible to produce any clamp profiles 1, 5, 9, 17, 21, 25 and also longitudinal slot profiles 4, 8, 12, 20, 24, 28.

Said embodiments of the tool have the advantage that the tools can be used for conventional clamping in a hand-held tool. The advantages obtained by the invention, i. the increase in the torque to be transmitted can be utilized when the tools are inserted into said clamping device with a clamping opening.

By placing the diametrically opposed driving strips 13a and the longitudinal strips 13b, the torque transmitted is parallel to the tool. The longitudinal strips 13b are so offset from the locking elements 16 that the axis of symmetry of the longitudinal strips 13b forms an acute angle to the axis of symmetry of the locking elements 16.

A preferred embodiment of the longitudinal strips 13b is a convex curved course of at least its driving surface. Especially in terms of production, the symmetrical profile of the longitudinal strips 13b brings certain advantages, so that the convex curved course of the opposite surface which is opposite to the driving surface is also another advantage. Both the surface driving arc and the opposing surface may substantially correspond to the arc described by the spherical or cylindrical blocking elements 16.

Claims (15)

PATENT CLAIMS A tool for hand-cutting, in particular a hammering and drilling, comprising a clamping shank in which at least one axially closed locking groove is formed and at least two driving grooves axially open to the free end of the clamping shank, characterized in that in the clamping shank (1, 5, 9, 17, 21, 25) at least one longitudinal groove (4, 8, 12, 20, 24, 28) is formed axially to the free end of the shank (1, 5, 9, 17, 21, 25) ) open, having different distances to the circumferentially adjacent driving grooves (2, 6, 10, 18, 22, 26), with the longitudinal groove (4,8,12,20,24,28) and the locking groove (3 , 7, 11, 19, 23, 27) partially overlap with their axial projections and the remainder of the axial projection of the locking groove (3, 7, 11, 19, 23, 27) is provided at its end as a support surface (3b, 7a, 11b, 19a, 23a, 27a). Tool according to claim 1, characterized in that two longitudinal grooves (8, 12, 20, 24, 28) are formed in the clamping shank (5, 9, 17, 21, 25), each with their axial The projection overlaps partially the axial projection of one of the two locking grooves (7, 11, 19, 23, 27) on the clamping shank (5, 9, 17, 21, 25). Tool according to Claim 2, characterized in that two longitudinal grooves (8, 12, 20, 24, 28) and two locking grooves (7, 11, 19, 23, 27) each are in the clamping shank (7). 5, 9, 17, 21, 25) formed diametrically opposite each other. Tool according to claims 1 to 3, characterized in that the axes (L) of symmetry of the longitudinal grooves (12, 24, 28) coincide with the axes (V) of symmetry of the locking grooves (11,23,27) by a sharp first angle ( a). Tool according to claims 1 to 4, characterized in that the longitudinal grooves (4, 8, 12, 20, 24, 28) exceed the axial length of the locking grooves (3, 7,11,19,23,27) by their length. . Tool according to claims 1 to 5, characterized in that the axial projection area of the longitudinal groove (4, 8, 12, 20, 24, 28) is smaller than the axial projection area of the locking grooves (3, 7, 11). 19, 23, 27). Tool according to claims 1 to 7, characterized in that the axial projection of the longitudinal groove (4, 12, 28) lies within the projection of the locking groove (3, 11). 27). Tool according to claims 1 to 7, characterized in that, with the locking grooves (3,11,27), the first orifice edges (3a, 11a, 27b) and the second orifice edges (4b, 12c, 28c) of the longitudinal grooves ( 4, 12, 28). Tool according to claims 1 to 8, characterized in that the longitudinal grooves (4, 8, 12, 20, 24, 28) have radially extending surfaces (4a, 8a, 12a, 20a, 24a, 28a) provided on the side coincident with the tool driving direction. Tool according to claim 9, characterized in that at least the surface (4a, 12a) on the driving side of the longitudinal grooves (4, 12) extends in a straight line and the bottom of the locking grooves (3, 11) has a circular arc shape, 4a, 12a) on the drive side of the longitudinal grooves (4, 12) forms a tangent to the bottom of the locking grooves (3, 11). Tool according to claim 9, characterized in that at least the surface (20a, 24a) on the driving side of the longitudinal grooves (20, 24) has a convex shape and the bottom of the locking grooves (19, 23) has a circular arc shape, (20a, 24a) at the entrainment side and the bottom of the locking grooves (19, 23) intersect. Tool according to claim 9, characterized in that at least the driving surface (28a) of the longitudinal grooves (28) has a concave shape and the bottom of the locking grooves (27) has a circular arc shape, the driving surface (28a) of the driving side and the bottom portion of the locking grooves (27) coincide. Tool according to one of Claims 1 to 11, characterized in that the longitudinal grooves (12, 20) have rectilinear and clamping second surfaces (12b, 20b) opposite the driving surfaces (12a, 20a). with the axis (V) of symmetry of the locking grooves (11, 19) a second angle (b). A tool according to any one of claims 1 to 12, characterized in that the longitudinal grooves (24) have opposite surfaces (24a) provided with convex-shaped second surfaces (24b). A tool according to any one of claims 1 to 12, characterized in that the longitudinal grooves (28) have opposing surfaces (28a) provided with second surfaces (28b) having a concave shape.